The Promising Role of the Gut in Treating Schizophrenia

Schizophrenia is a chronic, severe mental health condition thought to result from some combination of genetic and environmental factors. Imbalances in brain chemicals, such as dopamine and glutamate, also seem to play a role in schizophrenia.

Schizophrenia is diagnosed both by “positive” symptoms—among them hallucinations, delusions, and other disordered thinking—as well as “negative” symptoms such as reduced expression of emotion and speaking less. People who have this condition also may experience difficulties with cognitive functions such as decision making, planning, paying attention, and working memory.

There has been a great deal of talk about the role of gut flora, also known as the “microbiome,” and mental health. It may sound surprising, but severity of symptoms in depression, anxiety, autism, and now schizophrenia have been linked to imbalances in the gastrointestinal (GI) tract. More recent research has suggested a relationship between activity of the immune system, increased inflammation, the presence of food sensitivities, and imbalances in the GI tract in the presentation of schizophrenia.

Gut bacteria help regulate proteins and other substances that influence the brain’s development. One substance, “brain-derived neurotrophic factor” or BDNF, impacts the brain’s ability to develop new neurons and remain adaptable (referred to as neuroplasticity).

Our gut environment also appears to affect receptors in our brains. Receptors may be thought of as the equivalent of a keyhole on the surface of a neuron. Brain chemicals are like the “keys” that are designed to fit in a specific type of receptor. Once such type of receptor, the NMDA, is a type of glutamate receptor involved in, among other things, plasticity (or adaptability) of neurons related to memory and other functions. An unbalanced microbiome (gut bacteria, or flora) can lead to under-functioning NMDA receptors and variations in BDNF that may contribute to the production of schizophrenia symptoms.

Structural damage to the GI tract in people with schizophrenia has been linked to developing antibodies to brain cells in the hippocampus, amygdala, and frontal cortex. These brain areas are involved in working memory, emotion, motivation, decision making, and logical thinking—all of which may be impaired in people with schizophrenia.

Dr. Kaitlyn Nemani and colleagues reviewed the literature on the role of the gut in schizophrenia. Their review found that imbalances in the microbiome may be linked to structural damage in the gut, inflammation, and the development of autoimmune disorders. People who have schizophrenia, as well as their relatives, have been found to have a greater incidence of autoimmune disorders than people who either do not have or are not related to someone with schizophrenia.

In addition, structural damage to the GI tract in people with schizophrenia has been linked to developing antibodies to brain cells in the hippocampus, amygdala, and prefrontal cortex. These brain areas are involved in working memory, emotion, motivation, decision making, and logical thinking—all of which may be impaired in people with schizophrenia.

Gut flora imbalances may also play a role in increased sensitivity to gluten (a protein found in grains) and casein, which is the main protein found in milk and milk products. A growing body of research has found a relationship between gluten sensitivity that is not due to celiac disease and symptoms of both schizophrenia and autism.

Finally, imbalances in gut flora are linked to obesity and insulin resistance, both of which are linked to diabetes. People who have schizophrenia have an increased risk for these types of metabolic imbalances, and antipsychotic medication can further induce weight gain that can lead to metabolic problems and diabetes.

Novel Therapies to Balance the Gut

Dr. Nemani and colleagues suggest some nontraditional therapies that may complement existing medication and psychotherapy approaches for treating schizophrenia. These include:

Dietary changes. Although the evidence has been mixed, there is some data and also anecdotal reports suggesting that a subset of people who have schizophrenia benefit from avoiding gluten-containing foods (i.e., wheat, rye, barley, and other grains). Data regarding the impact of a casein-free diet on schizophrenia symptoms are lacking, but if your current treatment regimen provides insufficient relief, or you have GI symptoms that appear to worsen after consuming dairy, it may be worth going dairy-free for a few weeks to see if this improves your symptoms.

Antimicrobials. Minocycline (a form of tetracycline) is under investigation as an adjunct treatment in people with schizophrenia. It is thought to reduce inflammation and enhance glutamate neurotransmission.

Probiotics. Probiotics, or supplements containing “good bacteria,” may help balance gut flora and have been shown to positively impact mood, digestion, immunity, and weight. There does not appear to be risk associated with taking probiotics.

The last type of novel therapy discussed by the authors is fecal transplantation, or transplanting the fecal bacteria from someone with a healthy microbiome to a person who has a gut imbalance. Although this is considered a cutting-edge GI treatment for those who have inflammatory bowel disease, the authors conclude that a better understanding of the microbiome in those with schizophrenia is needed to know if this therapy is warranted.

As always, consult with your medical team when considering new therapies, conventional or complementary, such as those described above.

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Joel

March 31st, 2016 at
8:33 AM

I don’t know about you but this pretty impressive to see once again how all of the systems of the body can complement and interact with one another. Things that one would never initially suspect have anything to do with one another it turns out actually do play a significant role with each other. Pretty amazing.

geri

Marina

April 2nd, 2016 at
11:51 AM

I am wondering if one’s diet is monitored and modified very closely all throughout life if this could be a giant step toward helping prevent this disease? I know that you don’t usually associate the two, but what if there was the exact right balance maintained all throughout life. Do you think that this could help prevent schizophrenia?

Traci Stein

April 2nd, 2016 at
5:08 PM

Hi all, and thank you for reading. Marina, that is a great question, and I don’t think anyone can answer it as of yet. Biologically-based illnesses (of which schizophrenia is one) are challenging because there is still much we have yet to learn about what causes someone who is perhaps biologically vulnerable to developing an illness to wind up with that illness. Certainly, everyone with a family history of a condition does not end up with the same illness – a better understanding of the genetic roots of mental illnesses will ultimately shed more light on to what extent developing an illness is due to specific genes, etc. Yet, in many cases, biology is not equivalent to “destiny.” What I mean by that is that with many conditions, it is thought that there is some interaction between biological vulnerability to an illness and environmental triggers – whether these are emotional stressors, malnutrition, or other factors – as well. Certainly, for everyone, whether or not someone winds up developing a particular condition, good nutrition and other health habits, reducing exposure to environmental toxins, and having good stress management, etc. will make someone feel and do better – regardless of whatever condition they do or don’t have. The review by Dr. Nemani (mentioned above) does suggest that changes in the gut flora can help reduce symptom severity and improve quality of life. And that in and of itself is exciting and encouraging news.
Be well.

Marina

April 4th, 2016 at
4:03 PM

I find this work so fascinating, because wouldn’t it be incredible to learn that even small changes that we make in the composition of our gut could make such tremendous improvements in our health??? What a game changer that would be!

Asya

June 27th, 2018 at
4:49 AM

Hello, my name’s Janet. My mom is 52 yrs old. We live in Singapore. 20 yrs ago she was traumatised by her mother’s sudden passing away. After that she started skipping meals and became sedentary. She developed tumour in the colon. The doc said she was too weak to operate on so he gave her medicine. The tumour healed but colon remained obstructed which caused bloating, flatulence and pain radiating throughout her body. She also had and still have gastric problems so she was given an oval-shaped gastric tablet which she believed to be helping her but it wasn’t! She started experiencing voice sometimes talking inside her head but she learned to live with it. About a year ago she was diagnosed with gallbladder stone. She asked doc if he could remove the gallstone only but he said the stone would come back again, the whole gallbladder must be removed even if it’s healthy. She did as he said. After the surgery she avoided all fat foods and can eat only porridge. Other foods cause indigestion and none of the medicines help her. They cause excessive stomach acid and she can’t eat anything. The voice inside her head got worse! It mainly says negative stuff. Things she hates about the people she loves. Such as death, imprisonment and things we normally find disgusting. Not only about people she loves but also about God and saints! When told doc he advised endoscopy. After that doc only asked her to eat and take the same medicine which cause her more stomach acid! What is your opinion regarding her problem? Is there something wrong with her vagus nerve? She says the stomach acid goes to her head cause her the hallucinations. Can it happen? I heard about the gut-brain connection. Is it possible for the gut to send signals to the brain in the form of auditory hallucinations?

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